The Extended Lateral Orbital Approach: A Minimally Invasive Pterional Approach

surgical exposure to periand intra-Sylvian structures and allows direct access to parasellar structures. Despite its widespread use, the pterional approach presents several limitations: (1) potential postoperative temporal atrophy due to complete temporal muscle dissection; (2) injury to the frontal branch of the facial nerve; and (3) large incision and craniotomy, which may need longer healing time. Over the years, pterional craniotomy has seen many modifications, including extensions (intradural and extradural clinoidectomy, orbit unroofing, etc) and minimally invasive modifications as well. Among the minimally invasive pterional keyhole craniotomies, many have failed to address the limitations associated with the standard pterional craniotomy, and seldom were these approaches standardized. We present a minimally invasive keyhole craniotomy centered on the sphenoid ridge: the extended lateral orbital (XLO) approach (Figure 1). XLO is a novel approach developed to improve the limitations associated with the pterional craniotomy. This review illustrates the anatomic basis of the approach and its limitations and indications.